It's a bit too early to talk about tactics and strategies when the race has barely started its beta phase and is very likely to change in some areas for the final release.For now just keep playing and learn the general feel of the faction by yourself.

Then after the main release you can ask for any legit tips.

All I can say for now is that it seems Tau rely on upgrades to nullify their biggest weakness, which is close range/boarding game. Try out upgrades that improve your fleet's strength in close quarters, because it's not difficult to murder orkz, SM or IN with basic Tau fleet before they get within 3k, but once they do and you have no proper upgrades to respond, you're dead meat.

warning all of this is early and im very likely wrongyou can play them similar to SM with their homing torps and lots of probeswith a some awesome stealth upgrades making it theoretically possible to never get spottedunlike SM tho they dont have the speed to get away once they do get spotted, they compensate for it with raw forward firepower (LC and C,i need more time with the krootspheres to figure those out)turning broadside is a bad idea, weapons are can fire to their side and forward, each half 270°so to fire all you should be forward facing + the front is the side with 75 armor and a 75shield armor upgrade available as long as you dont lose your prow (but there is no way of targeting it?)so more forward facing slow marines with awesome upgrades than eldar